decode!/2 has invalid type signature for options

[DaniruKun]

Description

The usage example of decode!/2 with the as option does not match the actual type spec, causing dialyzer to complain.

Steps to reproduce

1. Create 2 functions in an Elixir module:

  def example do
	body = "some data"
	Poison.decode!(body, as: [%Video{}])
  end

  def example2 do
	body = "some data"
	Poison.decode!(body, %{as: [%Video{}]})
  end

2. Run dialyzer, it will fail with:

Function example/0 has no local return.
________________________________________________________________________________
lib/api/videos.ex:68:call
The function call will not succeed.


breaks the contract
(iodata(), Poison.Decoder.options()) :: Poison.Decoder.t() | no_return()

As you can see, example2 is valid, while example is not.